Fungos associados à microbiota terroir de vinhedos tropicais do Vale do Submédio São Francisco

Abstract

The terroir microbiome plays an important role in quality and safety of food, both in pre-harvest and post-harvest. Consequently, the understanding of factors constituting this microbial consortium in agronomic products can increase its benefits. Factors as soil, microorganisms, climate, geographic location of the vineyard and applied oenological practices are considered relevant and perform key role in wine production, since it has influence in development of each wine variety, in its quality and tipicity, becoming wine’s identity produced in a region. Grape (Vitis vinifera L.) is considered a complex matrix, source of several compounds, which constitute an ideal substract for microbial growth, thus being susceptible to contamination. The diversity study of microbial species of grape terroir is important to observe both positive or negative influences of these microorganisms into the characteristics of the final product. Thus, the objective of the present work was to evaluate the diversity of filamentous fungi in grape varieties of the Syrah, Tempranillo and Touriga Nacional, as well as the cultivation soil of two vineyards located in the Vale do Submédio São Francisco region. In order to do so, grapes and soil were collected in wineries located in the municipalities of Casa Nova-BA (winery 1) and Lagoa Grande-PE (winery 2) in the years 2016 and 2017. Morphological identification in association with a molecular molecular technique were used. The results show that, in the grapes, the genera Aspergillus, Penicillium and Cladosporium were predominant, representing 63.47 %, 26.67 % and 8.12 %, respectively. Through metagenomics approach the most abundant phyla found were Ascomycota, followed by Basidiomycota, and genera were: Alternaria, Aspergillus, Penicillium, Curvularia, Acremonium, Paramycospharella, Cladosporium, Ulocladium, Saccharomycopsis, Campylocarpon, Talaromyces, Erysiphe, Aureobasidium and Hanseniaspora. By the same molecular analysis, the Syrah 2 sample presented greater diversity in relation to the others, followed by Syrah 1, Touriga Nacional and less Tempranillo diversity samples. Some species were characterized as predominant, among these, most were identified as species of Aspergillus. In the soil samples of the vineyards the genera Aspergillus, Penicillium and Cladosporium were the most prevalent with 63.83 %, 27.66 % and 5.85 %, respectively. The soil metagenomics revealed a greater richness of OTUs than in the fruits, indicating greater biodiversity. There is prevalence of the Dothideomycetes class and the order Pleosporales in both samples. Together, the data found in this work reveal an overview of the fungal diversity in vineyards of the Submédio São Francisco Valley and may constitute the basis for other directed studies in this area.